Many recreational vehicles, especially custom trucks and conversion vans, include decorative and/or aerodynamic accessories such as spoilers, wings, and roof mounted luggage racks. For example, a typical conversion van usually includes a roof-mounted wing or spoiler that is attached on the roof near the rear of the vehicle. These wings or spoilers enhance the overall custom appearance of the vehicle, and also serve a functional purpose, in that they reduce drag and turbulence around the rear of the vehicle when the vehicle is travelling down the road, which greatly improves fuel efficiency.
Most conversion van companies buy stripped vans directly from original equipment manufacturers, and then customize the vehicles by installing lavish custom interiors, distinctive paint highlights or decals, custom wheels and tires, running boards, wings, spoilers, and roof racks. Most of the exterior accessories, such as the wings, spoilers and roof racks, are designed and built by specialty aftermarket supply companies or by the conversion company itself. These exterior accessories are usually constructed of molded fiberglass, and must be painted to match or accentuate the color of the vehicle itself. Because the vehicle itself is already painted, the accessories are preferably painted the desired color before they are installed so that no overspray can damage the factory paint on the vehicle.
At highway speeds, the roof-mounted accessories such as wings, spoilers, and roof racks can be subjected to very high loads and stresses from aerodynamic forces, and unless the accessories are adequately secured they are subject to vibration and/or breakage. Accordingly, these accessories must be screwed or bolted to the roof of the vehicle, usually by screws that are driven upwardly through the roof of the vehicle into the base of the spoiler or wing. Unfortunately, because the vehicles usually include custom upholstered headliners and trim, the roof mounted accessories must be installed very early in the assembly line process before the interior is finished to avoid damage to the custom interior work. However, because the accessories must be painted prior to installation, the paint on the accessories is likely to be nicked, scratched, or otherwise damaged as the vehicle goes through the assembly line. In that event, the damage must be fixed prior to delivery. The vehicle must be masked to prevent overspray from marring the custom finish, and then the exterior accessory is repainted. This install and repair process consumes precious time, labor, and material, and thus undercuts the efficiency of the assembly line.
Furthermore, if the accessory is broken or otherwise damaged during the useful life of the vehicle, the headliner inside the vehicle must be removed in order to gain access to the mounting screws so that the accessory can be removed for repair or replacement. Also, the fact that the headliner must be removed in order to install the accessories precludes most customers from installing their own aftermarket accessories, which hurts the aftermarket accessory industry as a whole.
Another problem with prior art attachment methods is that of stability. On most spoilers and wings, the body of the spoiler extends between two pads or feet, and the feet are attached to the roof of the vehicle. Also, because most modem spoilers are manufactured by a vacuum molding process, the shape of each foot must be straight or slightly tapered so that the spoiler can be extracted from the mold without damaging the foot or other parts of the spoiler. Unfortunately, these straight or tapered feet have a relatively small amount of contact area on the roof, which tends to lessen the overall stability of the finished product and which increases the chances that the accessory will vibrate or oscillate at high speeds.
Accordingly, there is a need for an improved device for attaching roof mounted, aftermarket accessories to motor vehicles that allows the accessories to be installed and removed without removing the headliner in the vehicle, and that can be installed at or near the end of the assembly line so that the accessory will not be subjected to possible damage during the conversion process. There is also a need for an improved device for securing aftermarket accessories to the roofs of motor vehicles that enhances the overall stability of the accessory and that is suitable for use on vacuum formed items.